This invention relates to propellers, and in particular, to a hub assembly for translating rotational movement from a propeller shaft of a marine vehicle to the blades of a propeller.
It is known to propel a marine vehicle utilizing a propeller assembly mounted on a rotatable shaft. The propeller assembly includes propeller blades extending from a central hub. A motor rotates the drive shaft which, in turn, rotates the central hub and the propeller blades. A hub assembly is provided to interconnect the central hub to the drive shaft. As is known, rotation of the propeller blades extending from the central hub propels the marine vehicle through the water.
Typically, the propeller assembly is constructed as a unit wherein the propeller blades, the central hub and the hub assembly are mounted or removed from the drive shaft in unison. Typically, the central hub of the propeller assembly includes an outer cylindrical housing which is welded or otherwise attached to a plurality of propeller blades. The central hub also includes an inner cylindrical housing which is co-axial with the outer cylindrical housing and radially spaced therefrom. The inner housing is supported within the outer housing by a plurality of circumferentially spaced ribs. The propeller assembly further includes a hub assembly disposed within the inner cylindrical housing of the propeller hub assembly. The hub assembly includes a drive member having an inner surface which meshes with splines on the outer surface of the drive shaft and an outer surface. A bushing formed from a rubber or elastomeric material is provided between the inner surface of the inner housing and the outer surface of the drive member. The elastomeric bushing provides shock absorbency between the propeller hub assembly and the drive shaft.
It has been found that slippage may occur between the elastomeric bushing and the inner surface of the inner housing. Once slippage has occurred, the outer surface of the elastomeric bushing may overheat and change its characteristics such that additional slippage becomes more common. Consequently, once slippage has occurred, it becomes necessary to replace the propeller assembly in order to once again realize the power capabilities of the motor of the marine vehicle.
In addition, it is known that the drive shafts driven by the various motors for marine vehicles differ depending upon the manufacture. Consequently, individual propellers must be provided for the drive shafts of each motor brand. Maintaining an inventory of specific propellers for each brand of motor requires significant storage space and may be cost prohibitive.
Therefore, it is a primary object and feature of the present invention to provide a hub assembly for a propeller which discourages slippage between the coupling element and the inner surface of the inner housing.
It is a still further object and feature of the present invention to provide a hub assembly for a propeller which may be easily adapted for mounting propellers on the drive shafts of different manufacturers"" motors.
It is a still further object and feature of the present invention to provide a hub assembly for a propeller which is simple and inexpensive to manufacture.
In accordance with the present invention, a connection assembly is provided for interconnecting a propeller shaft to a central hub of a propeller assembly. The central hub extends along a longitudinal axis and includes an inner surface having a key extending therealong. The connection assembly includes an adaptor having an inner surface defining a passageway for receiving the propeller shaft therethrough and an outer surface having an longitudinally extending key extending therealong. The connection assembly further includes a tubular bushing having a first keyway for receiving the key of the adaptor in a mating relationship and a second keyway for receiving the key of the central hub in a mating relationship.
The inner surface of the adaptor may include a plurality of splines which form a mating relationship with the propeller shaft. The key of the adaptor has a first narrow end and a second wider end. Similarly, the first keyway of the bushing includes a first narrow end and a second wider end. The adaptor may include an enlarged head extending radially from a first end thereof. The enlarged head is engageable with the central hub. It is further contemplated that the adaptor include a stop member adjacent an end of the key of the adaptor for limiting insertion of the key of the adaptor into the first keyway of the bushing.
It is contemplated that the bushing be formed of a resilient material. A locking nut is mountable on the propeller shaft for retaining the adaptor and the bushing thereon. A washer is disposed on the propeller shaft adjacent the locking nut.
In accordance with a still further aspect of the present invention, a propeller assembly is provided for mounting on a rotatable propeller shaft of a water craft. The propeller assembly includes a hub structure extending along a longitudinal axis. The hub structure includes an outer surface having a plurality of circumferentially spaced blades projecting therefrom and an inner surface having a longitudinally extending key projecting therefrom. The propeller assembly also includes an adaptor having an inner surface defining a passageway for receiving the propeller shaft therethrough and an outer surface having a longitudinally extending key extending therealong. A tubular bushing is also provided. The tubular bushing has a first keyway for receiving the key of the adaptor in the mating relationship and a second keyway for receiving the key of the hub structure in a mating relationship.
The key of the adaptor has a first narrow end and a second wider end. Likewise, the first and second keyways of the tubular bushing include first narrow ends and second wider ends. In addition, the key of the hub structure has a first narrow end and a second wider end.
The adaptor may include an enlarged head extending radially from a first end thereof. The enlarged head of the adaptor is engageable with the. hub structure. A locking. nut is mountable on the propeller shaft for retaining the adaptor and the bushing thereon. A washer is disposed on the propeller shaft adjacent the locking nut.
In accordance with a still further aspect of the present invention, a propeller assembly is provided for mounting on a rotatable propeller shaft of a watercraft. The propeller assembly includes a central hub defining an inner surface having a plurality of circumferentially spaced keys therealong. An adaptor has an inner surface defining a passageway for receiving the propeller shaft therethrough and an outer surface having a plurality of circumferentially spaced keys therealong. A tubular bushing has a first end including a plurality of circumferentially spaced recesses therein which define keyways for receiving corresponding keys of the adaptor in a mating relationship and a second opposite end including a plurality of circumferentially spaced recesses therein which define keyways for receiving corresponding keys of the central hub in a mating relationship. Each of the keys of the central hub has a first narrow end and a second wider end. Likewise, each of the keys of the adaptor has a first narrow end and a second wider end. In addition, each of the keyways of the bushing includes a first narrow end and a second wider end.
The adaptor may include a stop member adjacent the wider ends of the keys of the adaptor for limiting the insertion of the keys of the adaptor into the keyways in the first end of the bushing. A washer and lock nut are mountable on the propeller shaft for retaining the adaptor and the bushing thereon.